Question

How can I get access to the, for example, TextView, from the onClick method assigned to the, for example, ImageView? The TextView and ImageView make up the ListView item.

In my item.xml I have:

<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
> 
<ImageView
    android:id="@+id/img"
    android:layout_width="wrap_content"
    android:layout_height="fill_parent"
    android:onClick="onImgClick"
    />      
<TextView android:id="@+id/text"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    />
</LinearLayout>

And in my ListActivity I have onImgClick method:

 public void onImgClick(View v) {
    TextView tv = (TextView) v.findViewById(R.id.text);
tv.setText("Hello world!");
} 

But the View v – this is ImageView, so in this method I have Fatal Exception:

java.lang.NullPointerException

on the line:

tv.setText("Hello world!");

I know this isn’t correct way to get access to the TextView. And I know that I can use onListItemClick(ListView l, View v, int position, long id) according to the whole ListView. but I want to achieve this from the ImageView onClick method.

Answer 1

I have resolved my problem. I need only to set id on my LinearLayout:

android:id="@+id/main_layout"

And next do something like that:

public void onImgClick(View v) {
    LinearLayout linearLayout = (LinearLayout) v.getParent();       
    TextView textView = (TextView) linearLayout.findViewById(R.id.text);        
    textView.setText("Hello world!");
}